transcendental
adj 1. transcendent, superior, or surpassing
2. (in the philosophy of Kant) (of a judgment or logical deduction) being both synthetic and a priori, of or relating to knowledge of the presuppositions of thought
3. philosophy, beyond our experience of phenomena, although not beyond potential knowledge
4. theology, surpassing the natural plane of reality or knowledge; supernatural or mystical
Transcedentalism. 3=====D
He wrote mostly about nature. Only some of his poems were bout death or sad things. (His family wasn't really healthy. Only 2 out of 6 of his kids outlived him, and pretty much all his family members died of diseases.)